a
\(\frac{1}{{{\lambda _{K\alpha }}}}\,\, = \,\,R\,{(Z - 1)^2}\,\,\left[ {\frac{1}{{n_1^2}} - \,\,\frac{1}{{n_2^2}}} \right]\,\)

\( \Rightarrow \,\,\frac{1}{{{\lambda _{K\alpha }}}}\,\, = \,\,R\,\,{(Z - 1)^2}\,\left[ {\frac{1}{{{1^2}}} - \frac{1}{{{2^2}}}} \right]\)

\( \Rightarrow \,\,\,\frac{1}{{{\lambda _{K\alpha }}}}\, = \,\frac{{3\,R\,\,{{(Z - 1)}^2}}}{4}\,\,,\,\,R\,\, = \,\,1.097\,\, \times \,\,{10^7}/m\,\,\)  અને

\(\frac{1}{R}\,\, = \,\,912\,\,\mathop A\limits^ \circ  \)

\({\lambda _{K\alpha }} = \,\,\frac{4}{{3\,R\,\,{{(Z - 1)}^2}}}\,\,\,\)

\( \Rightarrow \,\,{\lambda _{K\alpha }} = \,\,\,\frac{{1216}}{{{{(Z - 1)}^2}}}\,\,\mathop A\limits^ \circ  \)